Steam-engine cylinder



militia Nrrnn STATES PATENT FFICQ WALTER J. ALLEN, OF ERIE,PENNSYLVANIA,

STEAM-ENGINE CYLINDER.

SPECIFICATION forming part of Letters Patent No. 251,809, dated January3, 1882.

Application filed May 12, 1881. (No model.)

Toall whom it may concern Be it known that I, WALTER JAY ALLEN, acitizen of the United States, a resident of Erie, Erie county,Pennsylvania, have invented new and useful Improvements in Steam-EngineCylinders; and I do hereby declare that the following is a full, clear,and exact description thereof, reference being had to the accompanyingdrawing and the letters or figures of reference marked thereon.

My invention consists in providing devices upon the cylinder of asteam-engine for admitting the steam which has just driven the piston inone direction to the opposite side of the piston, so as to cushion itand fill the entry-ports just previous to'the exhausting of said steamfrom the cylinder.

I am aware that means have heretofore been provided for transmittingsteam in the manner described above from one sideof the piston to theother for the purposes mentioned, and therefore I do not claim, broadly,devices for so doing. I

My invention consists in providing certain improvements in the devicesfor so conveying steam from one side of the piston to the other justprevious to the exhausting of the steam for thepurpose of cushioning thepiston and filling the entry-ports before the admission of steamthereto, which improvements will befully set forth in the followingdescription and claims.

My device is illustrated in the accompanying drawing asfollows: a singlefigure, which is a longitudinal vertical section, with the steamchestindicated by dotted lines, and having the parts indicated by letters ofreference, as followse A is the cylinder; B, the piston, which is shownin the positionit occupies just previous to the exhaust of steam at theopposite end of the cylinder, and also previous to the admission of livesteam at the end of the cylinder where the piston is.

a is the clearance-space.

D is a passage within the wall of the cylinder, spanning the piston whenat or immediately before it reaches the exhaust-line.

O is a check-valve located in the passage D at its end nearest themiddle of the cylinder, and opening from the body of the cylinderchambertoward the clearance-space.

forms of large ones.

0 is a plug or cage containing the check-valve,

and screws into the passage D from the out- .check-valve for keeping thesame closed except when opened by the pressure of steam. This springwill only be necessary when the plugs are so placed that gravity willnotact to close the valve, but may he used at any time, if desired.

The passage D maybe located at any point on the cylinder, as they do notcome in contact with the ports. If the steam-chest is on the side of thecylinder, they may be on top, and if the steam-chest is on top they maybe on the side of the cylinder. The passages I) are cored out in thecasting of the cylinder. The plugs 0 care of any metal desired-saybrassand are screwed into holes cored or drilled through the wall of thecylinder in contact with the passages D. This cage is provided with aport, 61, which registers with passage D, to allow the steam to escapefrom the cage into the passage. I am aware that a passage for thispurpose has been formed by using pipes outside the cylinder, and inwhich was located a check-valve5 but such a construction is notpractical on small engines, nor on many My device is adaptable to anyform of reciprocating engine.

The object of the check-valveO is as follows: When the piston passes themouth of the passage leading to the check-valve the steam raises thevalve and passes back of the piston into the clearance-space andentry-port and fills them. Immediately on this occurring the exhaustopens at the opposite end of the cylinder, and hence the pressure uponthe checkvalve 0 is removed, and it closes by the action of the steamwhich has already passed it, and keeps this steam in the spaces named toserve as a cushion and to save the steam necessary to fill these spaces.Immediately after the exhaust and the closing of the check-valve G theengine takes steam back of the piston and the check-valve prevents itfrom passing through the passage D.

In the device referred to as having passages in the wall of the cylinderit was necessary for the piston to start on its return-stroke by themomentum of the engine, so as to close the passage before the enginecould take steam; or, in other words, the engine could not take steamuntil the center was passed far enough to bring the piston over theinner opening of the passage. By my device it can take steam at anypoint, as the check-valve will close the passage D whenever there ispressure from that direction. The check-valve being arranged within theplug and within the passage D, it is easy of adjustment and quick toact, and, further, may be used on any size of engine.

I am aware that passages with check-valves have been used for thepurposes shown, but not with the check-valves placed in a detachableplug or cage. Iam also awarethatin pumps and in other machines valvesare often put into detachable cages, and so I do not broadly claim sucha manner of setting the valve; but the construction I show is peculiarlyadvantageous in the construction of steam cylinders, as above set forth.

What I claim as new is- In asteam-cylinder, a passage formed within thewalls of said cylinder for admitting steam from the body of the cylinderto the clearancespaces immediately before the exhaust takes place, saidpassage having at one end a cage provided with a port registering withthe passage, and a Valve inserted from the outside of the cylinder andretained in said cage by a plug closing the outer end of said cage,which valve opens by pressure from the body of the cylinder-cavit y andcloses by pressure from the clearance-space, substantially in the mannerdescribed.

In testimony that I claim the foregoing I have hereunto set my hand this9th day of May, 188].

WALTER JAY ALLEN.

Witnesses:

J NO. K. HALLooK, W. R. EDELEN.

